1. Technical Field:
This invention relates in general to an improved data access and storage device, and in particular to an improved actuator arm for a disk drive. Still more particularly, the invention relates to a system and method for improving the bending, torsional stiffness, and shock resistance of a disk drive actuator arm.
2. Description of the Prior Art:
Generally, a data access and storage system consists of one or more storage devices that store data on storage media such as magnetic or optical data storage disks. In magnetic disk storage systems, a storage device is called a hard disk drive (HDD), which includes one or more hard disks and an HDD controller to manage local operations concerning the disks. Hard disks are rigid platters, typically made of aluminum alloy or a mixture of glass and ceramic, covered with a magnetic coating. Typically, two or three platters are stacked vertically on a common spindle that is turned by a disk drive motor at several thousand revolutions per minute (rpm).
The only other moving part within a typical HDD is the head stack assembly. Within most drives, one read/write head is associated with each side of each platter and flies just above or below the platter""s surface. Each read/write head is mounted on a suspension to form a head gimbal assembly (HGA). The HGA is then attached to a semi-rigid arm apparatus which supports the entire head flying unit. More than one of such arms may be utilized together to form a single armature unit.
Each read/write head scans the hard disk platter surface during a xe2x80x9creadxe2x80x9d or xe2x80x9cwritexe2x80x9d operation. The head/arm assembly is moved utilizing an actuator which is often a voice coil motor (VCM). The stator of a VCM is mounted to a base plate or casting on which is also mounted the spindle supporting the disks. The base casting is in turn mounted to a frame via a compliant suspension. When current is fed to the motor, the VCM develops force or torque which is substantially proportional to the applied current. The arm acceleration is therefore substantially proportional to the magnitude of the current. As the read/write head nears the desired track, a reverse polarity signal is applied to the actuator, causing the signal to act as a brake, and ideally causing the read/write head to stop directly over the desired track.
As the demand for storage capacity of disk drives continues to increase, more disks are being put in the same size form factor, and the heads are required to read and write in smaller areas on the disks. In addition, the dynamic performance of the mechanical components also must be improved to accommodate the aggressive increase in the track density and the reduction in disk-to-disk spacing. The mass/inertia of the actuator is a particularly important parameter for improving the seek time and reducing power consumption. The actuator arm is the most significant contributor to the actuator mass/inertia. The most effective way to reduce the mass/inertia of the actuator arm is to reduce its thickness. Unfortunately, reducing the thickness of the actuator arm also has the adverse effects of decreasing the arm""s stiffness, bending and torsional resonance, and shock resistance. Thus, an improved data access and storage device actuator arm is needed.
A hard disk drive has a rotatable disk and an actuator arm that pivots relative to the disk. The arm has a cantilevered mounting support with a suspension extending therefrom. A head gimbal assembly is secured to the suspension for reading/writing data to the disk. The mounting support is a two-piece design with a pair of virtually identical support elements. The distal end of each support element has an aperture with a tab that protrudes into the aperture. The tabs extend in opposite directions.
The support elements mount on top of each other in a matching alignment configuration. The proximal ends of the support elements closely receive a pivot assembly to secure them from relative movement. On the distal ends, the apertures of the support elements substantially align such that their tabs precise engage each other in an interference fit. The interlocking tabs and tight fitting pivot assembly combine structurally to give the assembled mounting support enhanced bending, torsional stiffness, and shock resistance.
Accordingly, it is an object of the present invention to provide an improved digital access and storage device.
It is an additional object of the present invention to provide an improved actuator arm for a disk drive.
Still another object of the present invention is to provide a system and method for improving the bending, torsional stiffness, and shock resistance of a disk drive actuator arm.
The foregoing and other objects and advantages of the present invention will be apparent to those skilled in the art, in view of the following detailed description of the preferred embodiment of the present invention, taken in conjunction with the appended claims and the accompanying drawings.